cregit-Linux how code gets into the kernel

Release 4.7 drivers/clocksource/qcom-timer.c

/*
 *
 * Copyright (C) 2007 Google, Inc.
 * Copyright (c) 2009-2012,2014, The Linux Foundation. All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>

#include <asm/delay.h>


#define TIMER_MATCH_VAL			0x0000

#define TIMER_COUNT_VAL			0x0004

#define TIMER_ENABLE			0x0008

#define TIMER_ENABLE_CLR_ON_MATCH_EN	BIT(1)

#define TIMER_ENABLE_EN			BIT(0)

#define TIMER_CLEAR			0x000C

#define DGT_CLK_CTL			0x10

#define DGT_CLK_CTL_DIV_4		0x3

#define TIMER_STS_GPT0_CLR_PEND		BIT(10)


#define GPT_HZ 32768


static void __iomem *event_base;

static void __iomem *sts_base;


static irqreturn_t msm_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; /* Stop the timer tick */ if (clockevent_state_oneshot(evt)) { u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE); ctrl &= ~TIMER_ENABLE_EN; writel_relaxed(ctrl, event_base + TIMER_ENABLE); } evt->event_handler(evt); return IRQ_HANDLED; }

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arve hjonnevagarve hjonnevag3046.88%125.00%
viresh kumarviresh kumar34.69%125.00%
Total64100.00%4100.00%


static int msm_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE); ctrl &= ~TIMER_ENABLE_EN; writel_relaxed(ctrl, event_base + TIMER_ENABLE); writel_relaxed(ctrl, event_base + TIMER_CLEAR); writel_relaxed(cycles, event_base + TIMER_MATCH_VAL); if (sts_base) while (readl_relaxed(sts_base) & TIMER_STS_GPT0_CLR_PEND) cpu_relax(); writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE); return 0; }

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stephen boydstephen boyd6170.11%480.00%
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Total87100.00%5100.00%


static int msm_timer_shutdown(struct clock_event_device *evt) { u32 ctrl; ctrl = readl_relaxed(event_base + TIMER_ENABLE); ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN); writel_relaxed(ctrl, event_base + TIMER_ENABLE); return 0; }

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viresh kumarviresh kumar511.36%125.00%
Total44100.00%4100.00%

static struct clock_event_device __percpu *msm_evt; static void __iomem *source_base;
static notrace cycle_t msm_read_timer_count(struct clocksource *cs) { return readl_relaxed(source_base + TIMER_COUNT_VAL); }

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stephen boydstephen boyd1995.00%375.00%
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Total20100.00%4100.00%

static struct clocksource msm_clocksource = { .name = "dg_timer", .rating = 300, .read = msm_read_timer_count, .mask = CLOCKSOURCE_MASK(32), .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static int msm_timer_irq; static int msm_timer_has_ppi;
static int msm_local_timer_setup(struct clock_event_device *evt) { int cpu = smp_processor_id(); int err; evt->irq = msm_timer_irq; evt->name = "msm_timer"; evt->features = CLOCK_EVT_FEAT_ONESHOT; evt->rating = 200; evt->set_state_shutdown = msm_timer_shutdown; evt->set_state_oneshot = msm_timer_shutdown; evt->tick_resume = msm_timer_shutdown; evt->set_next_event = msm_timer_set_next_event; evt->cpumask = cpumask_of(cpu); clockevents_config_and_register(evt, GPT_HZ, 4, 0xffffffff); if (msm_timer_has_ppi) { enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING); } else { err = request_irq(evt->irq, msm_timer_interrupt, IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING, "gp_timer", evt); if (err) pr_err("request_irq failed\n"); } return 0; }

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marc zyngiermarc zyngier6143.88%120.00%
stephen boydstephen boyd5841.73%240.00%
viresh kumarviresh kumar1410.07%120.00%
shawn guoshawn guo64.32%120.00%
Total139100.00%5100.00%


static void msm_local_timer_stop(struct clock_event_device *evt) { evt->set_state_shutdown(evt); disable_percpu_irq(evt->irq); }

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marc zyngiermarc zyngier2496.00%150.00%
viresh kumarviresh kumar14.00%150.00%
Total25100.00%2100.00%


static int msm_timer_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { /* * Grab cpu pointer in each case to avoid spurious * preemptible warnings */ switch (action & ~CPU_TASKS_FROZEN) { case CPU_STARTING: msm_local_timer_setup(this_cpu_ptr(msm_evt)); break; case CPU_DYING: msm_local_timer_stop(this_cpu_ptr(msm_evt)); break; } return NOTIFY_OK; }

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stephen boydstephen boyd56100.00%1100.00%
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static struct notifier_block msm_timer_cpu_nb = { .notifier_call = msm_timer_cpu_notify, };
static u64 notrace msm_sched_clock_read(void) { return msm_clocksource.read(&msm_clocksource); }

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stephen boydstephen boyd18100.00%2100.00%
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static unsigned long msm_read_current_timer(void) { return msm_clocksource.read(&msm_clocksource); }

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stephen boydstephen boyd18100.00%1100.00%
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static struct delay_timer msm_delay_timer = { .read_current_timer = msm_read_current_timer, };
static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq, bool percpu) { struct clocksource *cs = &msm_clocksource; int res = 0; msm_timer_irq = irq; msm_timer_has_ppi = percpu; msm_evt = alloc_percpu(struct clock_event_device); if (!msm_evt) { pr_err("memory allocation failed for clockevents\n"); goto err; } if (percpu) res = request_percpu_irq(irq, msm_timer_interrupt, "gp_timer", msm_evt); if (res) { pr_err("request_percpu_irq failed\n"); } else { res = register_cpu_notifier(&msm_timer_cpu_nb); if (res) { free_percpu_irq(irq, msm_evt); goto err; } /* Immediately configure the timer on the boot CPU */ msm_local_timer_setup(raw_cpu_ptr(msm_evt)); } err: writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE); res = clocksource_register_hz(cs, dgt_hz); if (res) pr_err("clocksource_register failed\n"); sched_clock_register(msm_sched_clock_read, sched_bits, dgt_hz); msm_delay_timer.freq = dgt_hz; register_current_timer_delay(&msm_delay_timer); }

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stephen boydstephen boyd10961.58%866.67%
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arve hjonnevagarve hjonnevag2614.69%18.33%
christoph lameterchristoph lameter10.56%18.33%
Total177100.00%12100.00%


static void __init msm_dt_timer_init(struct device_node *np) { u32 freq; int irq; struct resource res; u32 percpu_offset; void __iomem *base; void __iomem *cpu0_base; base = of_iomap(np, 0); if (!base) { pr_err("Failed to map event base\n"); return; } /* We use GPT0 for the clockevent */ irq = irq_of_parse_and_map(np, 1); if (irq <= 0) { pr_err("Can't get irq\n"); return; } /* We use CPU0's DGT for the clocksource */ if (of_property_read_u32(np, "cpu-offset", &percpu_offset)) percpu_offset = 0; if (of_address_to_resource(np, 0, &res)) { pr_err("Failed to parse DGT resource\n"); return; } cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res)); if (!cpu0_base) { pr_err("Failed to map source base\n"); return; } if (of_property_read_u32(np, "clock-frequency", &freq)) { pr_err("Unknown frequency\n"); return; } event_base = base + 0x4; sts_base = base + 0x88; source_base = cpu0_base + 0x24; freq /= 4; writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL); msm_timer_init(freq, 32, irq, !!percpu_offset); }

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stephen boydstephen boyd212100.00%4100.00%
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CLOCKSOURCE_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init); CLOCKSOURCE_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);

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stephen boydstephen boyd70367.14%1869.23%
arve hjonnevagarve hjonnevag17416.62%13.85%
marc zyngiermarc zyngier13412.80%27.69%
viresh kumarviresh kumar232.20%13.85%
shawn guoshawn guo60.57%13.85%
jeff ohlsteinjeff ohlstein50.48%13.85%
christoph lameterchristoph lameter10.10%13.85%
kumar galakumar gala10.10%13.85%
olof johanssonolof johansson0.00%00.00%
Total1047100.00%26100.00%
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